On the 63rd session of the 3rd Generation Partnership Project (3GPP, 3rd Generation Partnership Project) Radio Access Network (RAN, Radio Access Network) 1, four scenarios of Coordinated Multi-Point transmission (CoMP, Coordinated Multi-Point) were defined. The fourth scenario is that power transmission points including a macro site (Macro Site) and a remote radio head (RRH, Remote Radio Head) in a macro site region share one cell identity (Cell Identity). This architecture is also called a distributed antenna system (DAS, Distributed Antenna System).
In uplink transmission of a DAS system, in order that powers received at a base station (eNB, evolved Node B) from different user equipments (UE, User Equipment) are on roughly the same level to avoid inter-UE interference caused by a near-far effect, uplink power control is generally applied to the UEs. In the Long Term Evolution (LTE, Long Term Evolution) R-10 standard, the transmit power of a physical uplink shared channel (PUSCH, Physical Uplink Shared Channel), a physical uplink control channel (PUCCH, Physical Uplink Control Channel), and a sounding reference signal (SRS, Sounding Reference Signal) is decided by path loss (PL, Path Loss) estimated by a UE, as expressed by the following formula:PLc=referenceSignalPower−RSRP
where, referenceSignalPower is a reference signal power defined by a base station, and is obtained by the UE through cell-specific (cell specific) high layer signaling, and RSRP is a reference signal received power measured by the UE at common reference signal (CRS, Common Reference Signal) Port 0 or Port 1.
However, the actual receiving point in the uplink may be inconsistent with the actual receiving, point in the downlink. Therefore, the path loss also differs. The PL calculation method in the prior art supports only path loss calculation for one power transmission point, and is not accurate when the UE uses the path loss to control the uplink transmit power.